Downloading Super-Huge Files via FTP, SFTP, Http, etc.

It seems that more and more nowadays, Chilkat has customers needing to download gigantic files (many Gigabytes) using various protocols such as SFTP, FTP, or HTTP. These downloads can take a long time, even with a very good transfer rate. The longer the download time, the higher the probability that something goes wrong: network congestion, connectivity issues, server problems, etc. […]

SSH Authentication Options in sshd_config

The /etc/ssh/sshd_config file has an entry called AuthenticationMethods. Typically you would enter either: to indicate which authentication method should be required. You can also enter: to indicate that either authentication method should be required. You can also enter: to indicate that both authentication methods should be required. If a server requires both publickey and password, then call AuthenticatePwPk. If a […]

Binary vs Text Transfers (SFTP / FTP)

This post clarifies the topic of binary vs. ascii uploads/downloads for SFTP (Secure File Transfer over SSH) and FTP. Binary mode transmits bytes exactly as-is.   Text mode (also known as “ascii” mode) can modify line endings (CR’s and LF’s) to the canonical convention used on the remote system.  For example, Linux systems typically use bare LF line-endings, whereas text […]

SSH/SFTP Error: Must first connect to the SSH server

The following error is explained in this post: ChilkatLog: DownloadFileByName: DllDate: Apr 25 2018 ChilkatVersion: 9.5.0.73 UnlockPrefix: * Architecture: Little Endian; 64-bit Language: Cocoa Objective-C VerboseLogging: 0 SftpVersion: 3 Component successfully unlocked using purchased unlock code. Must first connect to the SSH server. –DownloadFileByName –ChilkatLog The above error can happen after a long period of inactivity. Let’s say your application […]

C# SFTP Upload from Byte[]

This example demonstrates how to open a remote file on an SSH/SFTP server, write to the file, and then close it. This is analogous to opening a local file, writing to it, and closing it. The SFTP protocol (i.e. Secure File Transfer over SSH), follows the same concepts as typical file I/O programming — i.e. open a file, read, write, […]

How to know that SFTP Upload was Transferred Successfully?

Question: In the online reference documentation, it says that “bool UploadFileByName(string remoteFilePath, string localFilePath)” will return true if success or false for failure. My question is that how does your component know that the file had been transferred successfully? Does it get ACK from SFTP server or that only means that client had sent the file successfully but not guarantee […]

SFTP vs. FTPS

Clarification on the acronyms “SFTP” and “FTPS” “SFTP” is the Secure File Transfer Protocol over SSH.  It is a protocol unrelated to the FTP protocol. (It is actually a subsystem of SSH.)  The Chilkat SSH / SFTP component is used for “SFTP”.  SFTP is achieved by connecting to an SSH server at port 22. On the other hand, the Chilkat […]